Callibaetis mayflies have begun their seasonal emergences on local stillwaters. They are the longest running mayfly hatch of the year in the Yellowstone area, beginning in May and running until sometime in October. Emergences and spinner falls are both very important for anglers. If fishing lakes and ponds isn’t your thing, Callibaetis also inhabit the Henry’s Fork of the Snake River, though that particular emergence doesn’t start until later in the summer.
